A computed tomography (CT) scanner includes an x-ray tube that emits x-ray radiation. The radiation traverses a subject or object located in a field of view and is attenuated thereby. A detector array detects the radiation traversing the field of view and produces a signal indicative thereof. A reconstructor reconstructs the signal to produce volumetric image data.
Computed tomography scanners configured for spectral imaging have included photon counting detector pixels. With such pixels, the generated signals include electrical currents or voltages, each having a peak amplitude or a peak height that is indicative of the energy of a detected photon. The signal is energy resolved and subsequently processed. The reconstructor reconstructs spectral and non-spectral volumetric image data.
Cardiac CT requires high fluxes to get sufficient signal-to-noise-ratio during fast gantry rotation as required to virtually freeze the heart motion during the scan. With a high flux cardiac CT scan, some of the detectors will receive high flux. For example, detectors receiving radiation traversing a periphery of the patient and/or the lungs of the patient, where the patient has only small attenuation, will receive high flux.
Unfortunately, photon counting detector pixels have a limited count rate. As a consequence, a CT scanner configured with photon counting detector pixels may not be well-suited for high flux cardiac CT studies.